Noticed gf (40/f) behaving strangely with nephew

Lately I’ve noticed my gf take an unusual interest towards my nephew. We’ve been living overseas for the past 10 years and have now moved back home and staying at my sister’s until we get our own place. My gf takes great care with her appearance, always wearing makeup & dressing nicely (skimpy sometimes). My sister’s son has grown pretty big physically but he’s very nerdy and shy.

We all notice him stealing glances at my gf’s body a lot, but it’s fine since he’s at that horny age & also he’s totally inexperienced with girls. She shows off a lot of skin, especially when she walks around in her bikini top in between sunbathing. Even my sister’s husband can’t help but perve on her.

She’s out by the pool a lot & lately I noticed her interacting with my nephew a lot.
Once I saw her doing her stretches while he watched. She was bent over at the waist while her legs were spread far apart. Her bikini bottom was wedged in her ass crack & there were pubic hairs sticking out the sides on the crotch area. He was staring intently at her & had a huge erection poking up under his shorts. When she was done she lay down next to him and asked him to rub lotion on her. She instructed him to rub almost everywhere, all over her outer breasts, under her arms, high up her thigh, over her ass cheeks, even partly in her crack, and when he worked on her legs, she curled her toes in pleasure. I recognized this as the sign that meant she was desperate for a dick to enter, doesn’t matter who’s. (I had seen it once before when I did the foreplay to get her to that level in a taxi, but then I decided to ask the old dirty driver to screw her instead)

When he was done, they switched and she started rubbing lotion on him. He was laying down with a huge erection poking up and seemed to joke about it as she rubbed his body.

At this point I was getting worried at what this could lead to so I walked up to them.

She was telling him that he needed new shorts since these were obviously too small for him. When she noticed me, she quickly finished up with the lotion and offered to do me next. It seemed a bit forced but I decided not to think the worst of things.
My nephew jumped in the pool while she worked on me. When he came back out, he was no longer erect but the wet pants stuck to his body and revealed the shape of his package clearly.

She yelled out “OK thats it. Go get changed, I’m taking you to the mall for new pants. Those are way too small for you.” A while later she drove him to the mall.

When they came back my nephew’s face looked wierd. It seemed pale and he had a scared expression or something. I went to see him in his bedroom and asked how it went. He said it was fine and I tried to find out more. I asked him if anything happened or if there was something on his mind etc.

Finally he opened up and said “Auntie helped me try on pants.”

I told him that she was probably just being helpful and still thought of him as a little kid. “Besides, it’s not like you were naked right? You’re wearing underwear aren’t you?”

He nodded and after a while told me what happened.

Apparently she went in the change room with him and insisted on helping him try on the pants. To do so she had to help stuff his package inside as she lifted the pants up. Then she also had to adjust his crotch from outside to fit them comfortably. As he grew erect she reached inside his pants to move his penis directly and tried placing it in different positions.

He woulnd’t say what happened after so I confronted my gf instead. I accused her of incest etc and she kept denying. I was almost defeated until I noticed the streaks of white along her thighs. She saw that I noticed it and immediately tried to change the subject. She reached down my pants and got me hard and started riding me.

As we had sex, I talked dirty to her about my nephew and she immediately started a long orgasm. I kept dirty talking about his big dick in her pussy etc and she finally gave up some details in between moans. She admitted it was very big and she loved seeing it ejaculate. She admitted to masturbating over him after he kept getting hard from looking at her body.

After the orgasms subsided, we never spoke of this again. I trusted that she would stop this behavior, but actually her crazy slut behavior really turned me on and part of me wishes she would continue.

Source: reddit.com/r/eroticliterature/comments/g7b2y0/noticed_gf_40f_behaving_strangely_with_nephew